Cyclonic separation apparatus for vacuum cleaners typically have a cyclonic chamber, the cyclonic chamber having a generally cylindrical shape. The shape of the cyclonic chamber helps to create a cyclonic fluid flow path as a dirt laden fluid is drawn through it. Any dirt separated from the fluid can then be collected in a dirt collection chamber, which may also form part of the cyclonic separation apparatus. When considering the size of the cyclonic separation apparatus, a compromise may have to be made between having a large enough capacity in the dirt collection chamber whilst maintaining a high degree of separation efficiency in the cyclonic chamber. In addition, the overall size of the vacuum cleaner can be greatly affected by the size of the cyclonic separation apparatus. Therefore in order to achieve reasonably sized vacuum cleaner with an acceptable level of performance, a trade-off has to be made between the size of the cyclonic separation apparatus, and its separation efficiency and dirt capacity.